8. A pot of water on a stove is heated to boiling. Relative to its surroundings, is the system of
the pot of water on the stove open or closed
to the exchange of energy and matter?
A. The system is closed to energy but open to
matter, and it gains energy when the
molecules collide.
B. The system is closed to energy and matter,
and energy is lost in the form of thermal
energy to the air and pot.
C. The system is open to energy and matter,
and it loses thermal energy when it moves
from the system to its surroundings.
D. The system is open to energy but closed to
matter, and energy is destroyed when it
leaves the system and moves into its
surroundings.

In a wind tunnel the speed changes as the cross sectional area of the tunnel changes. if the speed in a 6' x 6' square test section is 100 mph, what was the speed upstream of the test section where the tunnel measured 20' x 20'? use conservation of mass and assume incompressible flow. conservation of mass requires that as the flow moves through a path or a duct the product of the density, velocity and cross sectional area must remain constant; i. e., that ova-constant. a model is being tested in a wind tunnel at a speed of 100 mph if the flow in the test section is at sea level standard conditions, what is the pressure at the model's stagnation point? (a) the tunnel speed is being measured by a pitot-static tube connected to a u- tube manometer. what is the reading on that manometer in inches of water? (b) at one point on the model a pressure of 2058 psf is measured. what is the local airspeed at that point?

Explain the consequences of this addiction to the brain tissue

Cathy is pedaling down a steep hill on her bicycle and wants to be able to coast up the next hill, which is 25 meters high, without pedaling. cathy and her bicycle have a mass of 75 kg. assuming her bicycle is 100% efficient, what would her speed have to be?